Sensors come in many shapes and sizes, from motion detectors that signal lights to go on when we enter a room to Geiger counters that detect radiation loss. Sensors are used in commercial, industrial, and personal applications including cars, machines, aerospace, medicine, manufacturing, and robotics. Often, sensors help regulate and control existing operations, such as proximity sensors that assist in aircraft and marine applications and speed and position sensors that assist in automotive engine management. Current sensors monitor AC and/or DC current for different electrical systems.
The resolution of a sensor is the smallest change it can detect in the quantity that it is measuring. Often in a digital display, the least significant digit will fluctuate, indicating that changes of that magnitude are only just resolved. The resolution is related to the precision with which the measurement is made. A sensor's sensitivity indicates how much the sensor's output changes when the measured quantity changes. Sensors that measure very small changes must have very high sensitivities. In addition, sensors need to have a small effect on what is measured.
Some applications use sensors that provide highly accurate measurement values and other applications use sensors to quickly detect a high overdrive (ODR) current. For example, a 100 ampere (A) current sensor might be needed to measure an offset error caused by a 10 milli-ampere (mA) standby-current. Also, an ODR current of 1000 A may need to be detected fast, such as on the order of 5 micro-seconds (u-seconds). Shunt resistors in the current path have been used to detect ODR current. However, shunt resistors can affect the accuracy of current measurements.
For these and other reasons there is a need for the present invention.